Generally described, computing devices utilize a communication network, or a series of communication networks, to exchange data. Companies and organizations operate computer networks that interconnect a number of computing devices to support operations or provide services to third parties. The computing systems can be located in a single geographic location or located in multiple, distinct geographic locations (e.g., interconnected via private or public communication networks). Specifically, data centers or data processing centers, herein generally referred to as “data centers,” may include a number of interconnected computing systems to provide computing resources to users of the data center. The data centers may be private data centers operated on behalf of an organization or public data centers operated on behalf, or for the benefit of, the general public.
Anycast addressing and routing methodology enables multiple data centers to provide similar or identical content to client computing devices. Specifically, anycast enables multiple data centers (or computing devices within the data center) to establish affiliation with a network-accessible address, such as an internet protocol (IP) address. When a client computing device requests a resource at the network-accessible address, the client computing device may be routed to any of the multiple data centers, based on networking decisions made by intermediate devices (e.g., network routers). Generally, client computing devices may be routed to a topologically-nearest data center. Where data centers are physically or logically dispersed (e.g., across a geographic area), client computing devices may therefore automatically connect to a nearest data center, without requiring selection of a specific data center (or client knowledge that multiple data centers exist).